One cable with a DB-25 Male connector on one and and a DB-25 Male connector on the other
end (both end connectors are the same). This cable connects the center connector of the
switch box to the computer's parallel port connector. (see
Printer Cables )

One cable having a DB-25 Male connector on one end and a Centronics 36-pin Male
connector on the other end. The DB-25 Male connector plugs into the "A" plug on
the back of the switch box. The other end (the centronics connector) plugs into the back
of the first printer.

One cable having a DB-25 Male connector on one end and a Centronics 36-pin Male
connector on the other end. The DB-25 Male connector plugs into the "B" plug on
the back of the switch box. The other end (the centronics connector) plugs into the back
of the second printer.

Centronics 35 Female for the computer connection

DB-25 Female for each printer connection

For this type of switch box you will need three Centronics Male-to-DB25 Male cables

One to connect from the computer to the switch box

and one (per printer) to connect from the switch box to each printer

Note:

do not use if your printer requires IEEE-1284 cables, instead use an automatic type
switch box

Connectors -

The connector on the back of the computer is a DB-25 Female (25 pins)

The connector on the back of the printer is typically a Centronics 36-pin Female
connector